Thermal Adaptation

Thermal Adaptation of Paramecium

Temperature is an
all-pervasive environmental attribute that strongly influences the phenotype
of organisms, their abundance and distribution, as well as population dynamics.
In particular, the development and growth rate of ectotherms
depend heavily on temperature, because of the strong temperature effect on
biochemical reactions. Due to the observational evidence that global warming
has had a discernible influence on many biological systems, experimental
investigations on the impact of elevated temperatures on ectotherms’
ecophysiology and genetic diversity has caused
renewed interest.

Within this project we are investigating patterns of evolutionary temperature
adaptation at the molecular and phenotypic level in the protozoan Paramecium
caudatum. These investigations aim to predict
effects on the diversity and the response of P. caudatum
to climate change making use of experimental evolutionary approaches. In a recent study published in Molecular Ecology, we have shown e.g., that populations evolving at high temperatures in experimental microcosms were more tolerant to acute heat stress and had higher fitness at optimum temperatures compared to control populations.

Future
attempts are seeking to better understand evolutionary processes as well as
the potential and constraints of rapid temperature adaptation in Paramecium.
We address, for example, the hypothesis that the genetic capability of
ciliates for an epigenetic transition between phenotypes provides an adaptive
advantage for a rapid adaptation to new environments. We are also interested
in the mechanisms determining the speed of adaptation under different
timescales of evolutionary change. These investigations should combine
genomic, transcriptomic and phenotypic analyses of
laboratory selection experiments with eco-evolutionary modelling
approaches.